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March 64 R. E. PRICE ETAL WORK TRANSFER APPARATUS FOR MACHINE TOOLS 3Shee s-Sheec 1 Q 3 m MWWW A m w w A E A Filed Nov. 18, 1960 March 10,1964 E. PRICE ETAL WORK TRANSFER APPARATUS FOR MACHINE TOOLS 3Sheets-Sheet 2 Filed NOV. 18, 1960 INVENTORS RALPH E PRICE BY WILLIAE.HAPPEL ATTORNEY March 10, 1964 WORK Filed Nov. 18, 1960 R. E. PRICEETAL 3,124,257 TRANSFER APPARATUS FOR MACHINE TOOLS 3 Sheets-Sheet 3 zau0 MACH/NE MACHINE INVENTORS RALPH E. PRICE BY WILLIAM E.HAPPEL ATTORNEYUnited States Patent -O 3,124,257 WORK TRANFER APPARATUS FQR MAQHINETUOLS Ralph E. Price and William E. l lappel, Wayneshoro, Pa., assignorsto Landis Tool Company, Waynesboro, Pa. Filed Nov. 18, 19 59, Ser. No.70,197 3 Claims. (Cl. 214-41) This invention relates to transferapparatus for machine tools, particularly crank grinders, and moreparticularly, to transfer apparatus where unground workpieces are pickedup and ground workpieces are deposited at the same end of the machine.

Previous transfer devices in which the unground work was picked up atone side of the machine and the ground work was deposited at the otherside of the machine, had the hook supporting means spaced an amountequal to the distance between the point of operation of the machine andthe point of pickup for discharge. This distance had to be traversedbetween the removal of a ground workpiece and the insertion of anunground workpiece.

It is, therefore, an object of the present invention to provide atransfer device on which the load and unload hooks are positioned sideby side so that workpieces are supported in end to end relation.

Another object is to provide a transfer device on which the work holdingunits travel only the length of one workpiece between machine load andunload positions.

Another object is to provide a transfer device which can be adapted to amachine which receives workpieces from one side and discharges on theother side, or a machine which receives and discharges workpieces on thesame side.

Another object is to provide a transfer device in which the carriage hasa long range movement and a short range movement.

Another object is to provide means for operating the load and unloadhooks independently of one another.

PEG. 1 is a front elevation of a crank grinding machine and associatedwork handling apparatus.

FIG. 2 is an end elevation of a portion of the transfer apparatus,specifically the hooks and hook actuating mechanism.

FIG. 3 is a hydraulic and electric circuit.

The bed of a crank grinding machine is indicated by iii from which ismounted a grinding wheel support 11 and a work carriage 12. On workcarriage 12 are crank heads 13 and 14- having conventional clampingfixtures 16 for rotating a workpiece 15.

At the left end of the crank grinding machine is a conveyor mechanism 2%having a conveyor 21 which receives workpieces from a precedingoperation and also from the operation with which this invention isconcerned. Tae conveyor mechanism 259 also includes a conveyor 22 1 ichsupplies unground workpieces for the preceding operation The transferapparatus consists of a pair of support members 3% and 31 for supportinga horizontal member 32 which serves as a track for carriage 33. Carriage33 supports a pair of closely spaced crank handling hooks, load hooks 35and unload hooks 36. The means for actuating hooks 3S and 36 isdescribed in detail in US. Patent 2,867,058, granted January 6, 1959,and only such details as are essential to the present invention aredescribed here. Carriage 33 is provided with two movements which aredescribed as a traverse movement and a shift movement. The term traverseas used here refers to the movement of carriage 33 between conveyors 21and 22 and the machine.

The term shift as used here refers to the movement of carriage 33between the load and unload positions 3,l2d,257 Patented Mar. if 19%.:

2 either in relation to the machine or to conveyors 21. and 22.

The traverse movement is the same as disclosed in the above mentionedPatent 2,867,058. It consists of a rack 40 attached to track 32. Ahydraulic cylinder 41 having a piston 2 is mounted on carriage 33.Piston rod 33 of piston 42 is connected to traveler member 45 havingrollers 46 for movement longitudinally of carriage 33. Traveler member45 has rotatably mounted thereon a large pinion St) for engaging rack 49and a small pinion 51 for engaging shift rack 5'2 slidably mounted oncarriage 33. There is no connection between traveler member 45 andcarriage 33 except through pinion 51 and rack 52.. When traveler member45 is shifted by means of the traverse piston 42 which is mounted oncarriage 33, pinion 51 and rack 52 only, have means for rotating pinionin engagement with rack 44) to move the entire combination of travelermember 45, carriage 33, cylinder 41 and piston 42 along rack 4t) andtrack 32. As shown, pinions 5i and 51 are in a ratio of 3 to 1. Thisratio may be varied to conform to variations in traverse requirements.

The present invention differs from that disclosed in the above mentionedpatent in that the rack 52, instead of being attached to carriage 33, isslidably mounted on said carriage to provide a short traverse movementreferred to above as a shift movement. For this function, shift rack 52is connected through piston rod 53 with a piston 5% in cylinder 55.Cylinder 5:5 is also attached to carriage 33. An adjustable stop 4-7limits the movement of traveler member 45 to the left. Adjustable stop5'7 limits the movement of shift rack 52 to the left. For a shiftmovement, shift piston 54 and rack 52 move on carriage 33 in engagementwith pinion 51. For a shift left movement, pinions 5i) and rotate in aclockwise direction. Pinion 5b in engagement with rack moves to the leftmore rapidly than rack 52 and the difference is transmitted back throughpinion 5'1 and rack 52 and becomes the movement of carriage 33.

Operation At the end of the Traverse Right movement, traverse piston 32is in its left hand position with si ift piston i lin the left handposition, and the loader is in the Shift Left position with the emptyunload hooks 36 above the workpiece in the machine. This may beconsidered the starting position for the transfer cycle.

The signal to start the cycle comes from the Cycle tart Switch formanual start, or from the Traverse Right imit switch 25 1.8, with themachine operating automatically.

in either case, unload hooks 36 are in the Lift Down- Swing Up positionso that the starting signal would energize Unload Swing Down relaylllCR.

As shown in the above mentioned Patent 2,867,058, each set of hooks 35and 35 has a vertical lift movement and also a swinging movement. Thesemovements occur in sequence, never simultaneously.

The function of the swinging movement, hereafter referred to as Swing Upor Swing Down, is to move the cranks laterally into or out of clampingfixtures 1e and to position the hooks prior to a Lift Up movement toremove a workpiece from the machine or to swing the hooks away after aLift Down movement to deposit a workpiece in the machine.

The function of the vertical lift movement, hereafter referred to asLift Up or Lift Down, is to deposit the cranks in the fixtures 16 aftera Swing Down movement to free the hooks from the crank prior to a SwingUp movement or to move the hooks upwardly to lift a crank free of themachine prior to a Swing Up movement.

The right hand hooks which remove the finished workpiece from themachine and deposit on the conveyor 21 will be referred to as the unloadhooks. The left hand hooks which pick up a workpiece from the conveyor21 and deposit it in the machine will be referred to as the load hooks.

in the present invention, we are concerned only with the sequence of thetraverse and shift movements. The ift and swinging movements will bereferred to only where they have a direct bearing on the traverse orshift movements of the loader.

The traverse movement is the movement of the loader between the machineand conveyor. The shift movement is a secondary movement of the loaderin either of the end positions of the traverse movement, or even in anintermediate traverse position, if necessary.

In starting position, unload hooks 36 are in the Lift Down position andtheir first movement will be to swing down to a position below theworkpiece to remove the workpiece from the machine. Thus in the LiftDown position, Unload Lift limit switch ZZLS is closed.

If the machine has not been operating previously, the closing of theCycle Start Switch will energize relay ECRM.

Contacts ItCRiVi and TCRMZ will close to supply current for the entirecircuit.

Limit switch ZZLS being closed, will energize relay tiiCRL. Relaycontact ifvCRLZ will close in the circuit to Unload Swing Down relayTHCR.

Carirage 33, being in the Shift Left position, Shift Left limit switch261.5 will he closed to energize relay 14CRL and also relay contactlldCRLi in the circuit to relay lilCR will be closed.

Unload Swing Up relay llfiCR will be deenergized because of the openingof normally closed relay contact TSCRLX. Normally closed relay contactlitlCRl will be closed in the circuit to relay lllCR.

Thus, Unload Swing Down relay lllCR will be energized and will energizevalve solenoid 13 which shifts valve 76 to the left to direct fluidunder pressure to the upper end of Unload Swing Down cylinder 80 topiece the hooks under workpiece 15. The hooks left up to remove theworkpiece from the clamping fixture 16 and return to Swing Up position.

If the machine has been in operation, ergize relay llliCR will come fromthe Traverse Right imit switch 291.8 which is closed in the TraverseRight position to energize relay TSSCR. Relay contact 136CR1 closes in acircuit parallel to the previously described circuit for relay lliCR andcompletes a circuit through normally closed relay contact lllilCRl, toenergize relay lililCR and Unload Swing Down valve solenoid 18 with theresultant movement described above.

When unload hooks 36 move to the Lift Up position after picking up ashaft, limit switch ZZLS opens to deenergize relay lt'iCRL. Normallyclosed relay contact itiCRL lcloses to energize relay IZSCR. Contact125C111 closes in the circuit through normally closed relay contactsil6CR2 and TMCRT to Loader Shift Right relay HSCR.

The upward movement of the hooks continues through the Swing Up positionat the end of which limit switch Z a-LS is opened to deenergize relayTZCRL. Normally closed relay contact TZCRLT completes a circuit throughrelay contact TZSCRT, and normally closed relay contacts TMCRZ and lMCRlto relay 115CR.

Contact RTSCRZ energizes Loader Shift Right valve solenoid 22 whichshifts valve 75 to the left, directing fiuid to the left end of shiftcylinder 55, moving piston 54 and rack 52 to the right and rotatingpinions t) and 51 in a counter-clockwise direction.

Pinion St), in engagement with rack 49, moves carriage 53 to the right adistance greater than the piston movement because of the difference indiameter of pinions 5i? and 51, to position load hooks 35 with anunground shaft above fixtures 15. This movement of carriage 33 a signalto encloses the Loader Shift Right limit switch 27LS to energize relayISZCR. Contact 32CR2 closes to energize Load Swing Down relay 121CR andvalve solenoid 26.

Load Swing Down valve solenoid 26 shifts valve to the right, directingfluid under pressure to the upper end of Swing Down cylinder 91, movingpiston 92 downwardly and swinging the hooks 35 to place workpiece 15 infixtures 16.

The load hooks 35 then lift down and swing up, opening Load Swing limitswitch ZSLS to deenergize relay ifCRL. Relay contact 13CRL1 closes acircuit through relay contacts IECRLT and CRIi to energize LoaderTraverse Left relay HZCR and valve solenoid 19 which shifts valve 95 tothe right, directing fluid under pressure to the left hand end oftraverse cylinder 41, moving piston 42 and traveler 45 to the right.

Pinions 5G and 5f rotate in a clockwise direction causing pinion 59, inengagement with stationary rack 40, to move traveler 4-5 and carriage 33to the left. Carriage 33 moves to the left in the Shift Right position.When carriage 33 reaches the left position, the empty load hooks 35 areover the conveyor 21.

If there is no shaft in the pick-up position on the conveyor, limitswitch ZsflLS will be opened, relay 6CR will be deenergized, and relaycontact CRl in the relay lli2CR circuit will remain open to preventenergizing relay TZZCR, and thus prevent the Traverse Left movement.

In the Traverse Left position as described, the Traverse Left limitswitch ZSLS closes to energize relay CR. Relay contact 13SCR2 completesa circuit to energize Load Swing Down relay TZICR. Relay contact 121CR1energizes Load Swing Down valve solenoid 26 which again shifts valve 96to the right, directing fluid to the upper end of Load Swing cylinder91. Piston 92 moves downwardly to swing the load hooks 35 to pick up aworkpiece 15 from the conveyor 21.

Upon return to the Swing Up position, Load Swing limit switch ZSLS opensto deenergize relay 13CRL. Normally closed relay contact TSCRLI closes.In the meantime, relay contact 135CR1 closes to complete a circuit whichincludes relay contacts 13CRL1, 12CRL1, TZSCRI and 132CR1, to energizerelay lloCR.

Normally closed contact lllCRZ opens the circuit through normally closedrelay contact 1 6C111 to deenergize relay HSCR. Contact 116CR1 closesand completes a circuit through normally closed relay contact HSCRl toenergize Loader Shift Left relay lll lCR.

Relay contact 13CRL1 being closed as described above, the circuit torelay TMCR is completed through relay contacts IZCRLI, 116CR1 and HSCRI,and relay 114CR is energized. Relay contact TMCRZ closes to energizeLoader Shift Left valve solenoid 21 which shifts valve '75 to the right,directing fluid under pressure to the right hand end of Shift cylinder55, shifting carriage 33 to the left to position unload hooks 36 overconveyor 21.

Loader Shift Left limit switch 26LS closes to energize relay MCRL. Relaycontact 14CRL1 closes to complete a circuit through relay contact lltlCRl to energize Unload Swing Down relay llllCR.

Relay contact llllCRl closes to energize Unload Swing Down valvesolenoid 18 which shifts valve 70 to the left to direct fluid to theupper end of Unload Swing cylinder 8t Unload hooks 36 swing down todeposit the ground crankshaft on conveyor 21. The unload hooks 36 thenreturn to Swing Up position, but not in the Lift Up position.

At the end of the Swing Up position, Unload Swing limit switch Z Z-LS isopened to dcenergize relay 12CRL. Normally closed relay contact TZCRLTcloses to energize Traverse Right relay 1-13CR. Relay contact 113CR1closes to energize Traverse Right valve solenoid 20 which shifts valve95 to the left, directing fluid under pressure to the right hand end oftraverse cylinder 41.

Piston 42 moves traveler 45 to the left, causing pinions 5i) and 51 torotate in a counterclockwise direction. Pinion 51, rotating in acounter-clockwise direction in engagement with rack 40, causes carriage33 to traverse to the right to position unload hooks 36 above workpiece15 in the machine to await the completion of the grinding operation andthe beginning of another transfer cycle.

We claim:

1. A work transfer apparatus for a machine tool comprising a supportmember, a horizontal track on said support member, a carriage on saidtrack, Work handling means on said carriage, means for traversing saidcarriage between two terminal positions, said traversing meanscomprising a piston and cylinder on said carriage, one of which isattached to a traveler member, said traveler member having a pair ofpinions, a rack on said track in engagement with one of said pinions, arack on said carriage in engagement with the other of said pinions,movement of said traveler member relative to said second rack causingrotation of said pinions whereby to traverse said traveler member andsaid carriage relative to said first rack to traverse said carriagebetween said two terminal positions, and means to actuate said secondrack to rotate said pinions to move said carriage relative to said firstrack whereby to provide a short range traversing move ment of saidcarriage in any position on said track.

2. A work transfer apparatus for a machine tool comprising a supportmember, a horizontal track on said support member, a carriage on saidtrack, means for tnaversing said carriage between a position adjacentthe point of operation of the machine tool and a position for picking upand depositing workpieces, said carriage having two sets of workhandling hooks spaced less than the distance between said two positions,a movable member having a pair of pinions, a rack on said track inengagement with one of said pinions, a rack on said carriage inengagement with the other of said pinions, a piston and cylinderconnected to said movable member and having a stroke which is apredetermined fraction of the distance moved by said carriage totransfer the work handling hooks between said point of operation andsaid pick up and deposit position,

to move said carriage between the point of operation and the point ofpick-up and deposit, a second piston and cylinder connected to the rackon said carriage and having a stroke which is a predetermined fractionof the center to center distance between said two sets of hooks tosuccessively position each of said sets of hooks in operative relationto said point of operation or said point of pick-up and deposit.

3. A work transfer apparatus for a machine tool comprising a supportmember, a horizontal track on said support member, a carriage on saidtrack, means for traversing said carriage between a position adjacentthe point of operation of the machine tool and a position for receivingunfinished workpieces and discharging finished Workpieces, said carriagehaving two sets of work handling hooks in adjacent relation, a movablemember on said carriage having a pair of pinions, a rack attached tosaid track in engagement with one of said pinions, a rack slidablymounted on said carriage in engagement With the other of said pinions, apiston and cylinder on said carriage connected to said movable member,said racks and said pinions being arranged to amplify the movement ofsaid piston and cylinder to move said carriage between the point ofoperation of the machine tool and the point of receiving unfinishedworkpieces and discharging finished workpieces, a second piston andcylinder connected to said slidably mounted rack, the movement of saidslid ably [mounted rack being amplified by said pinions and said otherrack to move one set of hooks out of operative relation and the otherset of hooks into operative relation either at the point of operation ofthe machine tool or at the position for discharging a finished workpieceand picking up an unfinished workpiece.

References Cited in the file of this patent UNITED STATES PATENTS2,653,502 Meyer Sept. 29, 1953 2,867,068 Balsiger Jan. 6, 1959 2,894,616Young July 14, 1959 2,978,117 Thompson Apr. 4, 1961

1. A WORK TRANSFER APPARATUS FOR A MACHINE TOOL COMPRISING A SUPPORTMEMBER, A HORIZONTAL TRACK ON SAID SUPPORT MEMBER, A CARRIAGE ON SAIDTRACK, WORK HANDLING MEANS ON SAID CARRIAGE, MEANS FOR TRAVERSING SAIDCARRIAGE BETWEEN TWO TERMINAL POSITIONS, SAID TRAVERSING MEANSCOMPRISING A PISTON AND CYLINDER ON SAID CARRIAGE, ONE OF WHICH ISATTACHED TO A TRAVELER MEMBER, SAID TRAVELER MEMBER HAVING A PAIR OFPINIONS, A RACK ON SAID TRACK IN ENGAGEMENT WITH ONE OF SAID PINIONS, ARACK ON SAID CARRIAGE IN ENGAGEMENT WITH THE OTHER OF SAID PINIONS,MOVEMENT OF SAID TRAVELER MEMBER RELATIVE TO SAID SECOND RACK CAUSINGROTATION OF SAID PINIONS WHEREBY TO TRAVERSE SAID TRAVELER MEMBER ANDSAID CARRIAGE RELATIVE TO SAID FIRST RACK TO TRAVERSE SAID CARRIAGEBETWEEN SAID TWO TERMINAL POSITIONS, AND MEANS TO ACTUATE SAID SECONDRACK TO ROTATE SAID PINIONS TO MOVE SAID CARRIAGE RELATIVE TO SAID FIRSTRACK WHEREBY TO PROVIDE A SHORT RANGE TRAVERSING MOVEMENT OF SAIDCARRIAGE IN ANY POSITION ON SAID TRACK.